I absolutely agree with not feeling guilty or bad when you have one of those days where your toddler watches a bit too much TV - it's not only ok, but sometimes necessary!! Mr Bean was my saving grace on many an occasion.
I have 15.5 mths between my two and I love the gap. We were very lucky in that we had a few weeks of jealousy in the beginning (though nothing major, just a few tantrums when I couldn't play when DD was feeding) but now DS LOVES DD and brings her toys, gives her loads of kisses and cuddles, loves to rub her head and tickle her. They play so well together, DD is besotted with DS and just stares and smiles and laughs at his antics.
The box of toys when feeding just didn't work for DS, I think he was too young or just didn't take any interest - he just wanted my attention. I got very good at feeding and walking, feeding and playing etc. Though he did love stickers so I got heaps of packets and would give him stickers and a book to stick/unstick them in when I was feeding.
A double pram or a pram and a carrier is also a must have for us.
Getting your toddler to help is great too, DS was just getting into the helping stage so I would ask him to get me a nappy or DD's dummy or a blanket - he thought it was awesome
Like someone else already mentioned, keeping the toddlers routine was a must for us. We tries as much as possible to make the the baby's routine work around the toddler and not the other way around. Dinner was still at 5pm at the table - I would feed DD at the table if need be, that kind of thing.
Also if you are going to change your toddler into a big bed then I'd do it either a while before they baby arrives or a while after - we put DS in a big bed two weeks ago and moved the cot out of his room a few days later. It was a little difficult in the beginning so I'm glad I didn't try it earlier.
Another great part of having them so close is that nearly every day I manage to get them both down for a nap at the same time (like now

)